Causes of Fertility/ or Barrenness of Soils. 177 
drilled with a solution of superphosphate, appear above ground 
in three days, and commonly in a week ; whereas on cold soils 
it is usually a fortnight before they can be seen. Harvests 
are much forwarder for the same reason ; there is often the dif- 
ference of from 10 days to a fortnight between sandy and clayey 
soils — a very important fact in our variable climate. As these 
soils do not retain moisture, and possess only slight capillary 
powers, they are subject to burn up with long-continued drought, 
and hence are very uncertain in their produce. In dry seasons 
the spring corn is often a miserable failure, the straw about a 
foot long, and the yield little more than the seed sown. The 
root crop for tlie same reason can seldom be depended upon. In 
a moist climate, by the aid of stimulating manures, a crop is 
pretty certain, but in other cases vegetation is often prema- 
turely arrested and mildew attacks the leaves, preventing further 
growth. Very nice management is required, exactly the reverse 
of that necessary for the clays ; in cultivating the latter our 
object is to loosen and render as friable as possible, for which 
purpose we plough repeatedly, dress with long half-rotted manure, 
and burn the surface into ashes. On sands we plough but little 
and sow the seed immediately after the plough, so as to receive 
the benefit of the moisture which is brought to the surface, re- 
peatedly roll and consolidate by every means in our power, until 
we so force the particles together as to enable the soil to retain the 
moisture better. Owing to the absence of resistance, cultivation 
of sandy soils is very easy ; single horses may often be seen at 
plough. A pair of quick light horses are equal to about 100 acres. 
The poorer kinds of sands, those that contain from 80 to 90 per 
cent, of silica, are nearly as undesirable as the very poor clays. 
In cases, however, where it is practicable, great advantages have 
followed the application of marl, clay, or chalk : this has been 
largely carried out in parts of Norfolk, the clay and marl being even 
brought from consideiable distances ; small quantities, compai'a- 
tively speaking, are found when acted upon by frost and air to 
effect an alteration in the soil ; the dose, however, should not be 
niggardly, at least 70 to 100 yards per acre, laid on the surface 
as early in the winter as possible, and not ploughed in until all 
chances of frost are over. By such means we may in time pro- 
duce a sandy loam of considerable value. Natural sandy loams 
are often found occupying the valleys in sandy districts : they 
consist of a large amount of sand with a small, but sufficient, 
quantity of clay, and often lime, to remedy all those defects so 
apparent in the purer sands ; and hence such soils are amongst 
the most valuable known, being adapted to the growth of almost 
every crop. Never wet, unless resting on a retentive subsoil, they 
yet retain sufficient moisture to keep the roots moist ; not porous 
VOL. XVI. N 
